Mueller Electric Test Clips Battery clip 617443 - Mueller BU-40A-0, The Mueller Electric BU-40A-0 battery clip features a steel, black finish and a maximum clamping range of 19 mm. It is designed for secure connections, with a total length of 58 mm, ideal for various electrical testing applications. Typically used in automotive and electronics troubleshooting, this alligator clamp ensures reliable conductivity and grip. Mueller BU-40A-0 Battery Clip Nickel-Plated Steel 19mm Clamping Range